PGE sets drain date for Roslyn Lake

It's been said for several years now that Roslyn Lake's days have been numbered, but now it's clear just how many days the local landmark has left.

Portland General Electric, the lake's owner, told The Post last week that it plans to cut off Roslyn's water supply Monday, May 5, which essentially would eliminate the lake by Friday, May 9. (Weather conditions could affect that timeline.

'It's a moment of history for the company,' said John Esler, PGE hydroelectric project manager. 'As it gets down to the last couple of days, it's a moment people are going to pause and think about.

'Nobody's looking back at this decision - it was the right decision to make - but at the same time, there's the loss of a neat old powerhouse, a neat lake and one of the area's oldest parks,' he said.

Roslyn Lake was created to collect water from the Sandy and Little Sandy rivers, producing hydroelectric power at the Bull Run powerhouse.

The $17 million decommissioning of the 95-year-old Bull Run Hydroelectric Project - which will allow the Sandy and the Little Sandy to flow unimpeded from Mount Hood to the Pacific Ocean and restore habitat for threatened fish and wildlife - spelled doom for the man-made lake, as its water sources were marked for elimination.

The Marmot Dam was destroyed last summer, and the Little Sandy dam, which provides Roslyn Lake with most of its water, will be dismantled this summer.

Roslyn Lake Park, one of the Sandy area's most popular attractions, closed Sept. 23.

Currently, the lake is filled with water from the Little Sandy River. That water travels from the river's dam to the lake via a mile-long flume. The lake water then is transferred out slowly to PGE's hydroelectric power station, where it generates electricity.

'On May 5, no more new water will be coming down the flume into the lake,' PGE spokeswoman Elaina Medina said. 'The water in the lake will continue to go to the powerhouse, they think for a couple more days. When they can't practically generate any more power for the powerhouse, they'll shut it down.'

At that point, the water will start to ooze out of the ground and evaporate, Medina said.

'They think - depending on the weather and lakebed conditions - it will take through the end of May to totally dry up,' she said.

The kill date for the lake is slightly earlier than originally anticipated.

'The date was set as we were looking at the workload we had to get done this summer before the fall rains,' Esler said.

PGE estimates that by May, the Little Sandy River will begin to see lower flows. With that in mind, PGE decided the amount of energy that could be generated didn't warrant the wait until summer.

'To drag another one or two weeks of the power project is not worth the effect on the decommissioning,' Essler said. 'You just got to pick a date and get started.'

In anticipation of Roslyn's demise, the Oregon Department of Fish and Wildlife lifted all bag and size limits on the lake Feb. 1.

Fishing enthusiasts have the opportunity to catch as much rainbow trout, smallmouth bass, yellow perch and bluegill fish as they want until May 5.

It's still uncertain what will become of the parkland and the former lake site.

Essler says that with the immediate tasks of the decommissioning at hand, the future of the site is an afterthought.

'Nothing's come to the surface,' Essler said regarding potential buyers. 'But it's fair to say we've been so busy trying to figure out how to do the decommissioning, that it's where all our focus has been.'

Even if PGE had a buyer lined up for the former Roslyn Lake site, the utility company is compelled to monitor the site for three years.

'Our responsibilities on that site don't end this summer,' Essler said. 'Part of the plan is that we have to monitor the site for noxious weeds, do some replanting.'

Essler said PGE is also considering the possibility of saving the powerhouse as a historic attraction.

Once the lakebed is dry, work crews will knock down the lake walls to begin to re-contour the land.

At some point in July, PGE will disassemble the Little Sandy's concrete dam, a much smaller undertaking than the dynamite-powered destruction of the Marmot Dam.

'They say they can get that done with a jackhammer in one morning,' Medina said. At this point, the former lake will be a giant sand pit, a perfect place to sort out the pieces of the flume, which will be removed by helicopter late in the year.

'The lake will not be a recreational facility in the summer; it will be a construction site,' Essler said. 'We just want to finish the removal successfully, do a good, efficient job, and get it done.'

For more information on Roslyn Lake and the decommissioning of the Bull Run Hydroelectric Project, visit www.portlandgeneral.com.